Piper PA-18 N623MP accident near Sterling, Alaska

Probable cause

The airplane owner improper fabrication of a fuel line, and subsequent inadequate inspection by an aviation mechanic, resulting in a loss of engine power.

NTSB analysis

According to the pilot, the accident flight was the first flight after a major rebuild of the airplane. After completing ground runs on the engine, he and a passenger departed for a test flight. During the initial climb, approximately 600 feet above the ground, the engine lost power. He elected to land in a snow-covered field and during the landing the airplane nosed over. Substantial damage was sustained to both the front and rear lift struts on the right wing. A postaccident inspection of the fuel system by the pilot revealed a flap of rubber inside a flexible fuel hose that was of significant size to restrict fuel flow to the engine. The fuel hose was fabricated by the airplane owner, under the supervision of the mechanic. The fuel hose which was fabricated out of flexible automotive hydraulic line was not an approved aircraft-grade fuel hose.

Text from the NTSB. Open the NTSB docket for ANC11CA013 for the full record.